Time for me to geek out.
No. Ajak is NOT the physically strongest Eternal. Ikaris is stronger than Ajak. Gilgamesh is stronger than both of them put together.
https://www.marvel.com/characters/ikaris/in-comics
https://www.marvel.com/characters/gilgamesh/in-comics
Allow me to suggest a comparable strength scale.
Most of Tony Stark's armor suits (with one exception being the Hulkbuster) make him superhumanly strong.
Armored Stark is not physically stronger than Thor.
Asgardian Thor is pretty darn strong and his true strength has not been truly shown in the MCU.
That said, Thor is not physically stronger than Hulk. Not even close. And that strength gap widens the madder Hulk gets. Gamma rage.
The producers (and Marvel) had some
rational for de-powering Ajak. Why neuter the character almost completely if the change was done to lessen an anticipated amalgamation issue among Eternal characters from the audience's point-of-view? Why
not strip Ajak of concussive comic energy blasts, teleportation, superspeed flight BUT
left her with superhuman strength along with her molecular manipulation power (which is the only thing that stayed true to the character)?
I don't know. Seems like they re-made the leader as the weakest
human Eternal so that she would be the easiest kill.